Tonsillar Hypertrophy

Enlargement of the palatine tonsils causing mechanical obstruction of the oropharyngeal airway or of swallowing, independent of infection. It is the commonest cause of obstructive sleep apnoea in children when combined with adenoid hypertrophy.

Natural history

Palatine tonsils are small at birth, enlarge rapidly from 1 to 3 years with antigenic exposure, peak between 3 and 7 years, and involute from around 8 years, becoming small and often barely visible in adults. The airway grows more slowly than the tonsil in early childhood, which is why the ratio of tonsil to airway is least favourable in the preschool years and why symptoms peak then.

Grading of tonsillar size, the Brodsky scale, based on the proportion of the oropharyngeal width occupied:

• Grade 0: tonsils within the tonsillar fossa.
• Grade 1: less than 25 percent.
• Grade 2: 25 to 50 percent.
• Grade 3: 50 to 75 percent.
• Grade 4: more than 75 percent, that is kissing tonsils.

Size correlates only loosely with symptom severity, since the position, the relative size of the airway, muscle tone and the contribution of the adenoid, tongue base and soft palate all matter. A grade 2 tonsil in a small child with a narrow pharynx can obstruct more than a grade 3 tonsil in a larger child. Symptoms, not grade, drive management.

Pathophysiology of obstruction in sleep

During sleep, pharyngeal dilator muscle tone falls. In a child with an already narrowed airway, negative inspiratory pressure produces collapse and either partial obstruction with hypoventilation and hypercapnia, or complete obstruction with apnoea, arousal and desaturation. Repeated arousals fragment sleep, and the resulting sympathetic surges, intermittent hypoxia and systemic inflammation drive the cardiovascular, metabolic, growth and neurobehavioural consequences.

Consequences of untreated obstructive sleep apnoea in children

• Growth failure, through disrupted nocturnal growth hormone secretion and increased work of breathing. Catch up growth after adenotonsillectomy is well documented and can be dramatic.
• Neurobehavioural impairment: inattention, hyperactivity, aggression, impaired executive function and poor school performance. This is frequently misdiagnosed as attention deficit hyperactivity disorder, and a proportion of such children improve substantially after surgery.
• Nocturnal enuresis, particularly secondary enuresis.
• Systemic and pulmonary hypertension, right ventricular hypertrophy and cor pulmonale in severe long standing disease.
• Craniofacial changes from chronic mouth breathing.
• Metabolic effects including insulin resistance in obese children.

Causes of tonsillar hypertrophy other than physiological

• Recurrent infection with fibrosis and lymphoid hyperplasia.
• Infectious mononucleosis, producing acute massive hypertrophy that can obstruct the airway.
• Human immunodeficiency virus, with generalised lymphoid hyperplasia.
• Lymphoma, particularly with unilateral or asymmetric enlargement.
• Squamous cell carcinoma in adults.
• Post transplant lymphoproliferative disorder in an immunosuppressed patient.
• Tuberculosis and actinomycosis.

• Snoring, which is the near universal presenting symptom. Habitual snoring, that is snoring on more than 3 nights per week, is the threshold that warrants assessment.
• Witnessed apnoeas, gasping, snorting and choking during sleep, reported by parents.
• Restless sleep with frequent position changes, sleeping with the neck hyperextended or sitting up, and profuse sweating.
• Mouth breathing during sleep and during the day.
• Paradoxical chest wall movement in younger children.
• Dysphagia, slow eating, gagging, food avoidance particularly of meat and solids, and poor weight gain.
• Muffled or hot potato voice, and hyponasal speech where the adenoid is also enlarged.
• Daytime behavioural disturbance: hyperactivity, irritability, poor concentration and impaired school performance. Frank daytime sleepiness is less common in children than in adults.
• Secondary nocturnal enuresis.
• Morning headache.
• Failure to thrive.

Examination

• Brodsky grading of tonsil size, assessed with the mouth open and without a tongue depressor pushing the tonsils medially, which artificially increases the apparent grade.
• Assessment of the palate for submucous cleft before considering concurrent adenoidectomy.
• Mallampati or Friedman tongue position, and assessment of the soft palate and tongue base.
• Nasal examination and flexible nasoendoscopy to assess the adenoid, since combined obstruction is the rule.
• Growth parameters plotted on a chart, and body mass index.
• Cardiovascular examination for signs of pulmonary hypertension: a loud second heart sound, right ventricular heave and hepatomegaly.
• Assessment for craniofacial abnormality, Down syndrome features, neuromuscular disease and hypotonia.

Red flags demanding a different pathway

• Unilateral or markedly asymmetric tonsillar enlargement in an adult, or with ulceration, induration or fixation, indicating malignancy. Tonsillar asymmetry with a neck node in an adult is squamous cell carcinoma or lymphoma until proven otherwise, and biopsy or tonsillectomy is required.
• Rapid unilateral enlargement in a child, suggesting lymphoma.
• B symptoms of fever, night sweats and weight loss.
• Immunosuppression or transplantation.
• Severe obstructive sleep apnoea with cardiorespiratory compromise or failure to thrive, requiring urgent surgery.
• Acute massive hypertrophy with airway compromise in mononucleosis, requiring corticosteroid and airway support.

• History from a parent or partner, which is the foundation. Video recording of the child asleep on a phone is genuinely useful and readily obtained.
• Clinical examination with Brodsky grading and nasoendoscopy.
• Overnight polysomnography, which is the reference standard, giving the apnoea hypopnoea index, oxygen saturation nadir, carbon dioxide levels and arousal index. In children, an index above 1 event per hour is abnormal, with 1 to 5 mild, 5 to 10 moderate and above 10 severe.

Polysomnography is not required before surgery in an otherwise healthy child aged 2 to 12 years with clear symptoms and visible adenotonsillar hypertrophy. It is indicated where:

• The history and examination are discordant.
• The child is under 2 years.
• There is obesity, Down syndrome, craniofacial anomaly, neuromuscular disease, cerebral palsy, sickle cell disease or a mucopolysaccharidosis.
• Surgery is being considered where the benefit is uncertain.
• The severity will determine the level of postoperative monitoring.
• Symptoms persist after adenotonsillectomy.
• Overnight pulse oximetry as a practical alternative where polysomnography is not available. Clusters of desaturation confirm obstructive sleep apnoea and identify children needing high dependency care; a normal study does not exclude it and should not override a strong clinical history.
• Lateral soft tissue neck radiography for adenoid assessment where endoscopy is unavailable.
• Echocardiography where pulmonary hypertension is suspected.
• Full blood count, and Epstein Barr virus serology where mononucleosis is possible.
• HIV testing where lymphoid hyperplasia is generalised or unexplained.
• Imaging with contrast enhanced computed tomography or magnetic resonance imaging, and biopsy, for unilateral or suspicious enlargement.
• Drug induced sleep endoscopy in children with persistent obstructive sleep apnoea after adenotonsillectomy, and in complex cases, which identifies additional sites of collapse at the palate, tongue base, lateral pharyngeal walls and supraglottis.

Non surgical management

Appropriate for mild disease, as a temporising measure, and where surgery is contraindicated or declined.

• Intranasal corticosteroid, principally acting on the adenoid but with some effect on tonsillar size: mometasone furoate 50 micrograms per nostril once daily in children aged 3 to 11 years, for at least 6 to 8 weeks.
• Montelukast 4 mg daily aged 2 to 5 years, or 5 mg daily aged 6 to 14 years, alone or combined with intranasal corticosteroid, which reduces adenotonsillar size and improves the apnoea hypopnoea index in mild disease. Counsel about neuropsychiatric adverse effects.
• Weight management in obese children, which is essential and which is frequently the dominant factor in adolescents. Adenotonsillectomy is less effective in obese children, and persistent obstructive sleep apnoea after surgery is common in this group.
• Treatment of allergic rhinitis.
• Elimination of tobacco smoke exposure.
• Continuous positive airway pressure, which is effective but poorly tolerated in young children and requires specialist paediatric sleep service support. It is used where surgery is contraindicated, where obstructive sleep apnoea persists after surgery, and as a bridge before surgery in severe disease.
• Supplemental oxygen may improve saturation but does not treat obstruction and risks worsening hypercapnia. It is not a substitute for definitive treatment.

Adenotonsillectomy

Indications:

• Obstructive sleep apnoea or obstructive sleep disordered breathing with adenotonsillar hypertrophy. This is the dominant indication in children and has largely overtaken recurrent infection as the reason for surgery.
• Dysphagia and failure to thrive attributable to obstruction.
• Speech abnormality from obstruction.
• Craniofacial or dental consequences of chronic mouth breathing.
• Suspected malignancy requiring histology.
• Coexisting recurrent tonsillitis meeting frequency criteria.

Timing:

• Do not delay in a child with severe obstructive sleep apnoea, failure to thrive or cor pulmonale.
• A period of watchful waiting with medical therapy is reasonable in mild disease in an otherwise well child, since some improve spontaneously.

Technique

• Adenotonsillectomy is usually performed, since combined obstruction is the norm and treating only one site leaves residual obstruction.
• Intracapsular tonsillectomy, also called tonsillotomy or partial tonsillectomy, removes the obstructing tonsil tissue while leaving a thin rim of tonsillar tissue on the capsule, so that the underlying muscle and its neurovascular structures are not exposed. Performed with microdebrider or coblation. It produces significantly less postoperative pain, faster return to normal diet and activity, and substantially lower secondary haemorrhage rates than extracapsular tonsillectomy. Efficacy for relieving obstruction is equivalent. The trade off is a small risk of tonsillar regrowth with recurrent obstruction, quoted at around 1 to 6 percent, and the absence of a complete specimen for histology.
• Intracapsular technique is now the preferred approach for obstruction in children without a significant infective history. Extracapsular tonsillectomy remains preferred where there is recurrent infection, where malignancy is a consideration, and where complete tissue is required.
• Extracapsular technique using cold steel dissection, bipolar diathermy or coblation, as described under recurrent tonsillitis.

Perioperative and postoperative management in obstructive sleep apnoea

This is where the risk in this group lies, and it differs materially from surgery for recurrent infection.

• Children with obstructive sleep apnoea have altered opioid sensitivity from recurrent hypoxia, with upregulation of central opioid receptors, and are at risk of respiratory depression at conventional doses. Use opioids sparingly and at reduced doses with monitoring.
• Codeine is contraindicated in children after tonsillectomy, following deaths in ultrarapid metabolisers, and particularly in those with obstructive sleep apnoea.
• Rely on regular paracetamol 15 mg/kg every 6 hours and ibuprofen 10 mg/kg every 8 hours, and dexamethasone 0.15 to 0.5 mg/kg intraoperatively, which reduces pain, nausea and airway oedema.
• Overnight admission with continuous pulse oximetry is required for children with an apnoea hypopnoea index above 10, an oxygen saturation nadir below 80 percent, age under 3 years, obesity, Down syndrome, craniofacial anomaly, neuromuscular disease, cerebral palsy, sickle cell disease, mucopolysaccharidosis, cor pulmonale or failure to thrive.
• High dependency or intensive care for the most severe cases, since respiratory complications, negative pressure pulmonary oedema and postoperative airway obstruction from oedema occur in the first postoperative night.
• Negative pressure pulmonary oedema can occur immediately after relief of chronic obstruction, presenting with pink frothy sputum and desaturation, and requires positive pressure ventilation and diuresis.

Outcomes

• Adenotonsillectomy resolves obstructive sleep apnoea in around 80 percent of otherwise healthy non obese children.
• Success rates fall to 50 percent or less in obese children, in Down syndrome, in craniofacial anomalies and in neuromuscular disease.
• Improvements in behaviour, quality of life, growth, enuresis and blood pressure are documented after surgery.
• Persistent symptoms require repeat polysomnography, drug induced sleep endoscopy to identify residual sites of obstruction, and consideration of continuous positive airway pressure, lingual tonsillectomy, supraglottoplasty, maxillomandibular expansion or, rarely, hypoglossal nerve stimulation in adolescents.

Adults with tonsillar hypertrophy

• Tonsillar hypertrophy is a less frequent cause of obstructive sleep apnoea in adults, where the palate, tongue base and lateral walls contribute more.
• Any adult with tonsillar hypertrophy, particularly if asymmetric, requires exclusion of malignancy with imaging and histology.
• Tonsillectomy for obstructive sleep apnoea in adults with grade 3 or 4 tonsils has good results, often as part of a multilevel procedure with palatal surgery.
• Adult tonsillectomy is markedly more painful and carries a higher haemorrhage rate than in children, and requires 2 weeks off work with realistic counselling beforehand.

Follow up

Review at 6 weeks with assessment of snoring, sleep quality, behaviour, growth and appetite. Repeat polysomnography at 6 to 12 weeks in children with severe preoperative disease and in all high risk groups, since residual obstructive sleep apnoea is common and is otherwise missed. Review all histology in adults.